The present invention relates to a selectable operational sequence system that selects a specific operational sequence according to the purpose of the arithmetic operation prior to the execution.
Conventionally, there are two kinds of arithmetic operations made available, i.e., a method called formula memory operation, which first inputs all the designated arithmetic formulas before executing operations in accordance with the preferential sequence of the designated operations (for example, both the multiplication and division precede the addition and subtraction with the priority given to the calculation of formulas in parenthesis), and the other method called sequential operation mode, which executes the designated operations by sequentially designating formulas according to the sequential key operations.
The former method has been widely made available, for example, by pocket computers and advanced functional calculators. This method smoothly inputs the designated data according to the established formula, for example, such as SIN3O, and yet, after entry of the designated formulas, incorrectly input data can be conveniently corrected as an advantage. The latter method has also been widely made available, for example, by a variety of electronic calculators and functional calculators. This method conveniently allows the operator to check the interim results of the formulas as required.
Nevertheless, since both of these methods employed by conventional calculators have been destined to strictly abide by either of such proper means, operators have been obliged to choose either of these methods when executing the designated formulas according to the purposes of the operations.